Hi.
I think I also have this mouse fetish. I am a programmer also and I like to use sidebuttons and other trick on mouse for speed up some tasks.
I hate heavy mouses. Maybe it is because I use fingertips to move mouse.
Now I use A4tech X710F at work, but i have to change because it is too heavy and I have pain in my smallest finger.
At home I use Icon7 Z300:
http://www.icon7.com/proinfo_01.aspx?pid=P_00000039&cid=C_00000010&cname=Gaming&pname=Z300&ccid=C_00000001
This is very lightweight, and it has programmable side buttons.
The only thing what missing is double click button.
I think I will try A4-Tech K5-52D at work. It looks good for fingertip usage, it has enough buttons (+programmable mouse gestures).
I hope it is not too heavy. (I didn't found the weight of it on net)

I've talked about the programmer's take on keyboard and chair, but I have yet to cover that other computing staple: the mouse. I was reminded when HMK referenced Ars Technica's History of the GUI: This was the mouse, invented by Douglas himself [in 1968] and built by one of his engineers. Nob...